78261031050421 has 2 divisors, whose sum is σ = 78261031050422. Its totient is φ = 78261031050420.

The previous prime is 78261031050343. The next prime is 78261031050467. The reversal of 78261031050421 is 12405013016287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72163563867396 + 6097467183025 = 8494914^2 + 2469305^2 .

It is a cyclic number.

It is not a de Polignac number, because 78261031050421 - 2⁹ = 78261031049909 is a prime.

It is a super-2 number, since 2×78261031050421² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78261031050491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39130515525210 + 39130515525211.

It is an arithmetic number, because the mean of its divisors is an integer number (39130515525211).

Almost surely, 2^{78261031050421} is an apocalyptic number.

It is an amenable number.

78261031050421 is a deficient number, since it is larger than the sum of its proper divisors (1).

78261031050421 is an equidigital number, since it uses as much as digits as its factorization.

78261031050421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 78261031050421 in words is "seventy-eight trillion, two hundred sixty-one billion, thirty-one million, fifty thousand, four hundred twenty-one".